As the information processing of electronic products becomes more and more high-speed and multifunctional, the amount of transmitted information continuously increases, the application frequency is required increase constantly, and moreover, the communication devices are continuously miniaturized, thereby the requirement for the electronic devices which are more miniaturized, lightweight and capable of high-speed information transmission becomes more and more urgent. At present, the operating frequency of the conventional communication device is generally more than 500 MHz, 1˜10 GHz for most of them; with the demand on transmission of large information in a short time, the operating frequency also increases continuously. But signal integrity problems arise with the increasing frequency. As a basic material of signal transmission, the dielectric property of the copper clad laminates is one of the major factors influencing the signal integrity. In general, the smaller the dielectric constant of the substrate material is, the faster the transmission rate will be, the smaller the dielectric loss tangent value will be, and the better the signal integrity will be. For substrates, how to reduce the dielectric constant and dielectric loss tangent becomes a hot issue in technical research in recent years.
In addition, in order to meet the requirements for PCB processing performance and terminal electronic products performance, the copper-clad substrate material must has good dielectric properties, heat resistance and mechanical properties, and also has good processing characteristics, high peel strength, low water absorption, excellent wet-heat resistance and UL94 V-0 flame resistance levels.
As we all known, there are a variety of materials with small dielectric constant and dielectric loss tangent characteristic, such as polyolefins, fluorine resins, polystyrene, polyphenylene ether, modified polyphenylene ether, bismaleimide-triazine resin and polyvinyl benzene resins. Although the resins above have good dielectric properties, they all have defects, such as processing difficulty and poor heat resistance, and therefore unable to meet the requirements of the copper-clad substrate.
CN102597089A discloses a resin composition comprising cyanate ester polymer and condensed phosphate ester, a cured resin, a sheet-like cured resin, a laminate body, a prepreg, electronic parts, single and multilayer circuit boards, which is used in and particularly suitable for single and multilayer circuit boards with high-frequency range above 100 MHz. However, the condensed phosphate ester employed has small molecular weight and large plasticity, which have a great impact on the heat resistance of the curing system, thus it cannot meet the requirements of high heat resistance.